1. The Axial Skeletal System

2. Skeletal System
206 Bones in body

3. Table 07.01

4. The Axial Skeleton Forms the longitudinal axis of the body
Divided into three parts
Skull
Vertebral column
Bony thorax

5. The Axial Skeleton
Figure 5.6a

6. The Axial Skeleton
Figure 5.6b

7. The Skull Two sets of bones Cranium Facial bones
Bones are joined by sutures

8. Cranial Bones Frontal Bone- makes up forehead
Supraorbital Forament- holes above eyes
Occipital Bone- back of head
Occipital chondyles- connect head to cervical vertebrae
Foramen Magnum- hole for brain stem
Parietal Bones
Bones on each side of the head

9. Human Skull, Anterior View
Figure 5.11

10. Human Skull, Inferior View
Figure 5.9

11. Human Skull, Lateral View
Figure 5.7

12. Cranial Bones Temporal Bone Skull bone by ears
Mastoid process- bump below ear
Mastoiditis- inflammation of air spaces of mastoid process
External Auditory (or Acoustic) Meatus- ear
Zygomatic Process- connects cheek bone to temporal bone
Styloid Process- projection inferior to external auditory meatus
Carotid Canal- where carotid artery runs

13. Human Skull, Lateral View
Figure 5.7

14. Cranial Bones Sphenoid Bone Bat or butterfly
Acts as a brace for the skull
Greater Wing
Lesser Wing
Sella turcica- where pituitary gland sits
Foramen Ovale- hole for cranial nerve 5 to pass to chewing muscle of the lower jaw
Optical Canal- allows optic nerve to pass to eye

15. Sphenoid Bone
Superior Orbital Fissure- cranial nerve controlling eye movements to pass through

16. Sphenoid Bone

17. Human Skull, Superior View
Figure 5.8

18. Human Skull, Inferior View
Figure 5.9

19. Cranial Bones Ethmoid Bone- makes up eye and nose
Cristi gali- hook of ethmoid that holds the menenges in place
Cribiform plate- separates nasal and oral cavity
Holes for nerves to reach the brain
Makes up part of superior and middle conchae (nasal walls)
Perpendicular plate
Divides nose into right and left
Deviated septum

20. Human Skull, Anterior View
Figure 5.11

21. Human Skull, Lateral View
Figure 5.7

22. Facial Bones Only mandible and vomer are single bones
Lacrimal bone- just inside eye
Has tear ducts
Mandible-jaw
Largest and strongest bone in face
Only moveable joint in face
Alveolar Processes-hold teeth in
Chondyloid or Chondyler process- posterior part of jaw that connects to temporal bone

23. Facial Bones
Mandible
Coronoid Process- anterior part of jaw that connects to temporal bone
Mental foramen- for nerves that carry info from lips and chin
Mandibular Foramen- nerves for lower teeth

24. Facial Bones Maxillary or Maxilla Fuse to form upper jaw
Alveolar processes- bones for teeth
Infraorbital foramen- holes below eyes
Palatine process- forms the anterior portion of the hard palate
Nasal Bones- forms bridge of nose
Palatine bones- make up the palate
Vomer- makes up bottom part of septum

25. Facial Bones Zygomatic Bones- cheek bones Hyoid Bone-
Only bone that doesn’t articulate with another bone
Serves as a base for the tongue

26. The Hyoid Bone
Figure 5.12

27. Sutures Immoveable joints between skull bones
Saggital suture- connects two parietals
Coronal- connects frontal and two parietals
Lambdoidal- connects parietals to occipital
Squamous- connects temporal to parietal

28. Sutures

29. Paranasal Sinuses
Hollow portions of bones surrounding the nasal cavity
Functions of paranasal sinuses
Lighten the skull
Give resonance and amplification to voice
Four bones with sinuses
Frontal
Maxillary
Sphenoid
Ethmoid

30. Paranasal Sinuses
Figure 5.10a

31. Paranasal Sinuses
Figure 5.10b

32. The Fetal Skull
The fetal skull is large compared to the infant’s total body length
Fontanels—fibrous membranes connecting the cranial bones
Allow the brain to grow
Convert to bone within 24 months after birth

33. The Fetal Skull
Figure 5.13a

34. The Fetal Skull
Figure 5.13b